The central theme of this program is to study aging of the human knee joint and its relationship to osteoarthritis (OA). The Administrative Core will focus efforts of the cores and projects on this theme, advance hypotheses and research directions and ascertain scientific progress. The core will provide administrative support for the most efficient utilization of resources. The core will maintain access to different sources of knee joints and cartilage and monitor sample processing by the cores and analysis by the projects. Core A also serves as the central unit for data management and maintains the database for all knee specimens that are studied in the program. The Specific Aims of the Administrative Core are: Aim 1. Monitor scientific progress in the individual projects. Aim 2. Promote interactions among the investigators in the program. Aim 3. Support young scientists and development of new projects. Aim 4. Provide access to knees and cartilage samples. Aim 5. Maintain central database. Aim 6. Perform statistical analysis. Aim 7. Coordinate all fiscal activities of the program. Aim 8. Ascertain responsible conduct of research. Aim 9. Enforce safety measures for work with hazardous materials. Aim 10. Distribute tissues and tissue extracts to outside investigators.